Bangalore has around 10,000 mud houses today, informs M.R. Yogananda, a doctorate in Civil Engineering from IISc. But isn’t it time we thought of mud as a medium for construction with cement costs spiralling?
“Irrespective of the cement costs, one has to think about ways to reduce material consumption in constructions, as most consume high energy in their production and transportation,” says Mr. Yogananda, who propagates sustainable methodologies in construction. In soil-stabilised blocks, we are looking at utilising mud excavated at the site itself, explains Mr. Yogananada.
Soil-stabilised blocks are a mixture of mud (72 to 75 per cent), with small portions of cement , sand and lime depending on the location. The silt-mud of Delhi will have to bring in coarse-aggregates into the mix, the sandy soil of Kanakapura would eliminate the necessity to blend sand, while acidic mud would have to get in lime water too. These blocks have the potential to be mixed with any industry/factory generated waste like the red mud, an off-shoot of any aluminium factory, or fly ash from the Raichur Thermal Power Station, he said.
Mr. Yogananda recollects comments people passed about his mud house that was built just before the rainy season in 1987. “It will collapse Sir, don’t take the risk,” many people told him. It is 27 years now but the test for mud construction was still the first rain ,” he says.
Says architect Neelam Manjunath, who specialises in a bamboo-and-mud combo in her constructions, “The strength that mud imparts is just incredible. I use the bamboo-and-mud combo for walls and columns too.” Architect S.N. Ramesh, who has built several apartments and a resort in Ramanagaram using mud blocks says that people have to necessarily use mud blocks only after determining the ratio of material mix required, as the scientific soil test is the decisive factor for stability.
But that’s not all. Mud blocks make sense only when left unplastered as the earthy look also eliminates the sand, cement and paint costs on wall. “The wisdom lies in training masons. The overall costs come down by nearly15 per cent if mud blocks are used, says Mr. Yogananda.